/*
Every divisor d of a number n has a complementary divisor n/d.

Let f(n) be the sum of the greatest common divisor of d and n/d over all positive divisors d of n, that is
$f(n)=\displaystyle\sum\limits_{d|n}\, \text{gcd}(d,\frac n d)$.

Let F be the summatory function of f, that is
$F(k)=\displaystyle\sum\limits_{n=1}^k \, f(n)$.

You are given that F(10)=32 and F(1000)=12776.

Find F(1015).

Anser:
Time:
*/
package main

import (
	"fmt"
	"time"
)

func main() {
	tstart := time.Now()



	tend := time.Now()
	fmt.Println(tend.Sub(tstart))
}